Get even! Producing a nice even color with your coloring pencil is all down to pressure. Push harder on your page for darker coloring, applying little pressure will producer a much lighter color. It is tempting to put lots of pressure on the pencil to produce the darkest color _ don't do it! Too much pressure will likely cause you to break your pencil leads, produce a scratchy finish to your coloring and give you less control. Instead, try applying your pencil with a little less pressure and use small circular motions with the pencil to get an even finish.
There's also a kind of colored pencils that's called water_coloured pencils. The way of application is just the same as colored pencils. However, with this media you can achieve a watercolor effect by dipping a brush in water and brushing along the colored areas with it. It's actually a fun media to try especially if you want to use a watercolor but find the mixing with water hard. It's easy to use as well.